Alpha-haloalkyl phosphonothioates



United States Patent 3,463,839 ALPHA-HALOALKYL PHOSPHONOTHIOATES Erik A. Regel, Mission, Kans., assignor to Chemagro gorporation, Kansas City, Mo., a corporation of New ork No Drawing. Original application Sept. 15, 1964, Ser. No. 396,753, new Patent No. 3,385,688, dated May 28, 1968. Divided and this application Nov. 16, 1967, Ser. No. 701,795

Int. Cl. C07f 9/40; A01n 9/36 US. Cl. 260-958 12 Claims ABSTRACT OF THE DISCLOSURE Compounds are prepared having R1 0 OR;

II/ P where R is alkyl of 1 to 8 carbon atoms, R is selected from the group consisting of alkyl of 1 to 8 carbon atoms, phenyl, chlorophenyl and benzyl, R and R taken together are CH (CH CH where n is an integer from 1 to 3 inclusive; R is selected from the group consisting of alkyl of 1 to 8 carbon atoms and chloroalkyl having 1 to 3 carbon atoms; R, is selected from the group consisting of alkyl of 1 to 8 carbon atoms, alkenyl of 3 to 8 carbon atoms, phenyl, alkylphenyl having 1 to 4 carbon atoms in the alkyl group, chlorophenyl, dichlorophenyl, trichlorophenyl, nitrophenyl and and X is halogen of atomic weight 35 to 80. The compounds are useful as herbicides.

This application is a continuation-in-part of application Ser. No. 357,761, filed Apr. 6, 1964, now Patent 3,346,669 and is a divisional application of application Ser. No. 396,753, filed Sept. 15, 1964 and now Patent 3,385,688.

The present invention relates to oc-ChlOIOfilkYl phosphononthioates.

It is an object of the present invention to prepare novel u-chloroalkyl phosphonothioates.

Another object is to devise a novel method of preparing such compounds.

A further object is to prepare novel herbicides.

An additional object is to prepare herbicides having selective post emergent herbicide activity.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

It has now been found that these objects can be attained by preparing compounds having the formula where R, is alkyl containing 1 to 8 carbon atoms, R is alkyl containing 1 to 8 carbon atoms, phenyl, halophenyl or benzyl or R and R taken together is Where n is an integer from 1 to 3 inclusive; R is alkyl containing 1 to 8 carbon atoms or hal oalkyl containing 1 to 3 carbon atoms, and R is alkyl of 1 to 8 carbon atoms, alkenyl of 3 to 8 carbon atoms, alkinyl of 3 to 8 carbon atoms, phenyl, halophenyl, dihalophenyl, alkylphenyl, nitrophenyl, trihalophenyl or i C=CHO 0 0111 and X is halogen of atomic weight 35 to 80. For the best results the alkyl groups contain 1 to 4 carbon atoms.

Examples of compounds within the present invention are O,S-dimethyl-u-chloroisopropylphosphonothioate, O-methyl-S-ethyl-a-chloroisopropylphosphonothioate, O,S-diethylwt-chloroisopropylphosphonothioate, 0-propargyl-S-ethyl-ot-chloroisopropylphosphonothioate, O-o-chlorophenyl-S-ethyl-a-chloroisopropylphosphonothioate, O-mchlorophenyl-S-ethyl-a-chloroisopropylphosphonothioate, O-p-chlorophenyl-S-ethyl-wchloroisopropylphosphonothioate, O-2,4-dichlorophenyl-S-ethyl-a-chloroisopropylphosphonothiate, O-methyl-S-butyl-a-chloroisopropylphosphonothioate, O-ethyl-S-butyl-a-chlorois0pr0py1phosphonothiate, O-phenyl-S-butyl-a-chloroisopropylphosphonothioate, O-rnethyl-S-secondary butyl-a-chloroisopropylphosphonothioate, O-p-nitrophenyl-S-methyl-a-chloro-a-methyl propylphosphonothioate, O-methyl-S-ethyl-a-chloro-a-methyl propylphosphonothioate, O,S-diethyl-oc-chloro-u-tmethyl propylphosphonothioate, O-isopropenyl carboxyethyl-Sethyl-a-chloro-a-methyl propylphosphonothioate, O-2,4,S-trichlorophenyl-S-ethyl-a-chloro-a-methyl propylphosphonothioate, O-mmethylphenyl-S-ethyl-u-chloro-u-methyl propylphosphonothioate, O-phenyl-S=buty1-a-chloro-a-methyl propylphosphonothioate, O-methyl-Sethyl-oc-chloro-a-methyl isoamylphosphonothioate,

3 O,S-diethyl-a-chloro-a-ethyl propylphosphonothioate, O-methyl-S-ethyl-a-chloro-a-ethyl amylphosphonothioate, O,S-dimethyl-ot-chlorocyclopentylphosphonothioate, O,S-diethyl-u-chlorocyclopentylphosphonothioate, O-ethyl-S-propyl-a-chlorocyclopentylphosphonothioate, O,S-diethyl-u-chlorocyclohexylphosphonothioate, O-ethyl-S-butyl-a-chlorocyclohexylphosphonothioate, O,S-diethyl-a-bromoisopropylphosphonothioate, O,S-dimethyl-a-bromoisopropylphosphonothioate, O-propyl-S-butyl-a-bromo-u-methyl propylphosphonothioate, O,S-dipropyl-a-chlorocyclobutylphosphonothioate, O-octyl-S-methyl-a-chloroisopropylphosphonothioate, O-ethyl-S-octyl-u-chloroisopropylphosphonothioate, O-methyl-S-3-chloropropyl-a-chloroisopropylphosphonothioate, O-ethyl-S-chloromethyl-u-chloroisopropylphosphonothioate, O-allyl-S-methyl-a-chloroispropylphosphonothiate, 0-2-0ctenyl-S-ethyl-a-chloroisopropylphosphonothioate, 0-2-0ctinyl-S-propyl-a-chloroisopropylphosphonothioate, O-2,4-xylyl-S-methyl-u-chloroisopropylphosphonothioate, O-4butylphenyl-S-ethyl-a-chloroisopropylphosphonothioate, O,Sdimethyl-ot-chloro-a-methyl nonylphosphonothioate, O,S-dimethyl-a-octyl nonylphosphonothioate, O-methyl-S-ethyl-a-chloro-ot-benzyl ethylphosphonothioate, O,S-diethyl-a-chloro-a-phenyl ethylphosphonothioate, O-methyl-S-butyl-tx-chlor0a-p-chlor0phenyl ethylphosphonothioate, O-2,4-dichlorophenyl-S-ethyl-a-chloroisopropylphosphonothioate, and O,S-dibutylu-chloro-ot-methyl propylphosphonothioate.

The compounds of the present invention are prepared by reacting equimolar amounts of a compound having the formula R OMe with a phosphorus containing compound having the formula A SR3 The reaction of the present invention can be carried out with excess of alcoholate or phenolate if desired.

The reaction is carried out at a temperature from room temperature up to 60 C. Usually an appropriate solvent is also used such as an alcohol, e.g., methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, butyl alcohol or hexyl alcohol, dioxane or a hydrocarbon, e.g. toluene, xylene, benzene, hexane, petroleum ether, aromatic naphtha or the like.

Examples of starting alcoholates and phenolates are sodium methylate, potassium methylate, lithium methylate, calcium ethylate, sodium ethylate, potassium ethylate, sodium octylate, sodium propylate, sodium isopropylate, potassium butylate, sodium secondary butylate, sodium phenolate, potassium phenolate, sodium O-cresylate, potassium m-cresylate, sodium p-cresyl-ate, sodium xylenylate, sodium p-chlorophenolate, sodioacetoacetic acid ester, sodium allylate, sodium propargylate, sodium salt of trimethylene chlorohydrin, sodium O-nitrophenolate, sodium-2,4,6-dichloropheno1ate, sodium 2,4,5-trichlorophenolate.

As the starting phosphorus compounds there can be used S-ethy1-ot-chloroisopropyl phosphonochloridothioate, S-methyl-a-chloroisopropyl phosphonochloridothioate,

S-butyl-ot-chloroisopropyl phosphonochloridothioate,

S-secondary butyl-a-chloroisopropyl phosphonochloridothioate,

S-methyl-OL-ChlOI'O-Ot-H'lfithYl propylphosphonochloridothioate,

S-ethyl-a-chloro-a-methyl propylphosphonochloridothioate,

S-butyl-a-chloro-a-methyl propyl-phosphonochloridothioate,

S-ethyl-u-chloro-u-methyl-isoamylphosphonochloridothioate,

S-ethyl-a-chloro-a-ethyl propylphosphonochloridothioate,

S-ethyl-a-chloro-oc-ethyl amylphosphonochloridothionate,

S-methyl-tx-chlorocyclopentylphosphonochloridothioate,

s-ethyl-a-chlorocyclopentylphosphonochloridothioate,

s-propyl-a-chlorocyclopentylphosphonochloridothioate,

S-ethyl-a-chlorocyclohexylphosphonochloridothioate,

S-butyl-a-chlor0cyclohexylphosphonochloridothioate,

S-ethyl-a-bromoisopropylphosphonobromidothioate,

S-methyl-a-bromoisopropylphosphonobromidothioate,

S-butyl-u-bromo-u-methyl propylphosphonochloridothioate,

s-propyl-u-chlorocyclobutylphosphonochloridothioate,

S-octyl-ot-chloroisopropylphosphonochloridothioate,

S-3-chloropropyl-a-chloroisopropylphosphonochloridothioate,

S-chloromethyl-ot-chloroisopropylphosphonochloridothioate,

S-propyl-a-chloroisopropylphosphonochloridothioate,

S-methyl-a-chloro-a-methyl nonylphosphonochloridothioate,

Selhyl-OL-ChlOI'O-0t-b6I1ZY1 ethylphosphonochloridothioate,

s-ethyl-u-chloro-a phenyl ethylphosphonochloridothioate,

S-butyl-a-chloro-a-p-chlorophenylethylphosphonochloridothioate,

S-isopropyl-u-ch10roisopropylphosphonochloridothioate,

S-isobutyl-u-chloroisopropylphosphonochloridothioate,

S-methyl-a-chloro-a-methyl butylphosphonochloridothioate,

S-6thyl-0c-ChlOI'O-0L-II1lhyl hexylphosphonochloridothioate,

S-ethyl-u-chloro-u-ethyl amylphosphonochloridothioate,

S-ethyl-a-chloro-a-propyl butylphosphonochloridothioate,

S-ethyl-a-chloro-rx-methyl heptylphos-phonochloridothioate.

The starting phosphorus compounds are prepared by reacting 1) phosphorus trichloride or phosphorus tribromide With (2) a ketone having the formula and '(3) a mercaptan having the formula R SH. Equimolar quantities of the three reactants are employed.

Representative ketones Which can be used are acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl isopropyl ketone, ethyl butyl ketone, dipropyl ketone, methyl t-butyl ketone, isobutyl hexyl ketone, ethyl octyl ketone, acetophenone, phenyl acetone and p-chloroacetophenone, cyclopentanone, cyclohexanone and cyclobutanone.

Representative mercaptans which can be employed are methyl mercaptan, ethyl mercaptan, propyl mercaptan, isopropyl mercaptan, butyl mercaptan, secondary butyl mercaptan, t-butyl mercaptan, amyl mercaptan, hexyl mercaptan, octyl mercaptan, Z-ethylhexyl mercaptan, 3-chloropr0pyl mercaptan and chloroethyl mercaptan.

EXAMPLE 1 S-ethyl-a-chloro-a-methyl propylphosphonochloridothioate Butanone (1 mole) and phosphorus trichloride (1 mole) were mixed at 0 C. and ethylmercaptan (1 mole) 1 was added dropwise while the mixture was kept below 10 C. by cooling and agitation. Hydrogen chloride was liberated and reaction mixture became yellow. After the addition of ethylmercaptan was completed the mixture was allowed to warm up to C. and agitation was 2 continued until hydrogen chloride evolution ceased. Carbontetrachloride (200 ml.) was added and the resulting solution was washed with water until the solution was almost neutral (pH 6). The carbon tetrachloride solution was dried over anhydrous sodium sulfate, filtered 25 When PBr is used in place of PC1 examples of the starting compounds formed are shown in Table 2.

Refractive R R R R B.P. index Me Me Me Br M.P Me- Et Et Br 1 5655 Me Me El: Br 100/0.005 1 5745 The compounds of the present invention are prepared as shown in Example 2.

EXAMPLE 2 Metallic sodium (0.07 mole) was added portionwise to 100 ml. of ethanol and the mixture was stirred until all the sodium was dissolved. To this ethanolic solution of sodium ethylate was added dropwise S-ethyl-a-chloro isopropyl-chloridophosphonothiate (0.07 mole). An exothermic reaction took place and the mixture temporarily reached 60 C. and immediate precipitation of sodium chloride occurred. The mixture was agitated for 2 hours and allowed to stand for an additional 15 hours at room temperature, until a pH of 7 was obtained. The mixture was then diluted with benzene and the benzene solution Washed with water, dried over anhydrous sodium sulfate, filtered and the solvent evaporated in a vacuum. The re' sulting crude O,S-diethyl a chloroisopropylphosphonothioate (0.06 mole) was obtained as a colourless oil. After purification by distillation in vacuum 0.05 mole of the pure ester was'obtained (72% yield) B.P. 70 C., n

The compounds of the present invention made by 'reacting the appropriate S-substituted-haloalkylhalothioate with the appropriate sodium alcoholate or phenolate in TAB E 1 the manner shown in Example 2 are set forth 1n Table 3.

TABLE 3 1 0 SR:

R1 0 OR; 0-1 H R ll R 2 R2 (El SR3 Compound Boiling Point Refractive o. R R- R R C./mm Hg. index 01 (48) 68/0.01 1. 5270 25 Cl -60/0.005 1. 5166 23 isoPr C1 70/0.02 1. 5055 C1 -85/0.04 1 5085 25 $001311 01 75/0.02 1 5058 ISOBu Cl 75/0.04 1 5052 Cl 75/0.15 1 5265 28 Cl /O.1 1 5095 25 Cl 1 5186 25 C1 C1 C1 C1 Me 01 --(CHz)4- C1 --(CH2)4- C1 2)r- Cl M 01 C1 C1 C1 Bu Cl C1(CH2)3 O1 Pinanyl Cl C1(CHa)s 01 Me 01 E1: 01 Me Cl El: 01 El; 01 31 Pr C1 32 lsoBu isoBu E1; 01 33 (CH2)5- E1; 01

TABLE 3.-Continued Compound Refractive N0. 1 R2 R3 R4 B.P. index Me Me 4953/0.005 1 4911 El; Me 58-62/0.008 1 5000 E1; E1; 80/0.02 1. 4825 E1; CHzC=CH 79/0.007 1. 4941" Et Ph 125/0.005 1. 5385 Et o-OlPh l30/0.005 1 5515 Et m-ClPh 135/0.01 1 5477 El; pClPh 128132/0.01 1 5477 Et 2,4-ClzPh 140/0.005 1 5574 Bu Me 7274/0.01 1 4812 Bu Et 96/0.01 1. 4861 B11 Ph l33/0.002 1. 5285 Bu p-OlPll 170/0.002 1. 5365 secBu Me 5962/0 05 1. 4897 Me p-NOzPh 180/0.07 1 5677 Et Me 81/0.06 1. 4972 Et Et 72/0.02 1 4932 El; 125130/0.04 1 5047 El; 2,4,5-Cl3Ph 168/0.3 1. 5638 Et m-CHaPh 128/0.01 1 5350 Bu Ph 150/0.005 1 5295 E1: Me 75/0.08 1. 4883 E1: Et 77/0.03 1. 4916 El; Me 10370.04 1. 4935 Me Me 83/0.08 l. 5127 26 ICHZCHZCHZ Et Et; 82/0.02 1. 4967 27 (llH CH CHa Pr Et 97/0.0l 1. 5028 28 CHQCHQCHZ Et Et 99/0.03 1. 5077 CH OHI 29 CHzCHzCH: Bu Et 130/0.01 1. 4981 CHzCHg 1 -C=CHCO1EC By substituting S-ethyl-a-brornoisopropylbromidophosphonothioate in Example 2 for the corresponding chlorido compound there was produced Qs-diethyl-a-bromoisopropylphosphonothioate, B.P. 79 C., 0.02 mm.; Refraction Index 1.5056 This is identified as compound 30 in the subsequent tables.

The compounds of the present invention can be used alone as herbicides but it has been found desirable to apply them to the plants or soil surrounding the plants, together with inert solids to form dusts or, more preferably, suspended in a suitable liquid diluent, preferably comprising water. They can be applied at widely varying rates, e.g. from 0.1-30 lbs./ acre.

There can also be added surface active agents or wetting agents and inert solids in the liquid formulations. The active ingredient can be from 0.01 to 95% by weight of the entire composition when it is employed in such formulations.

In place of water there can be employed organic solvents as carriers, e.g., hydrocarbons such as benzene, toluene, xylene, kerosene, diesel oil, fuel oil, and petroleum naphtha, ketones such as acetone, methyl ethyl ketone and cyclohexanone, chlorinated hydrocarbons such as carbon tetrachloride, chloroform, trichloroethylene and perchloroethylene, esters such as ethyl acetate, amyl acetate and butyl acetate, ethers, e.g., ethylene glycol monomethyl ether and diethylene glycol monomethyl ether, alcohols, e.g., ethanol, methanol, isopropanol, amyl alcohol, ethylene glycol, propylene glycol, butyl carbitol acetate and glycerine. Mixtures of water and organic solvents, either as solutions or emulsions, can be employed.

The novel herbicides can also be applied as aerosols, e.g., by dispersing them in air by means of a compressed gas such as dichlorodifluoromethane or trichlorofiuoromethane and other Freons, for example.

The herbicides of the present invention can also be applied with adjuvants or carriers such as talc, pyrophyllite, synthetic fine silica, attapulgus clay (attaclay), kieselguhr, chalk, diatomaceous earth, lime, calcium carbonate, bentonite, fullers earth, cottonseed hulls, wheat flour, soybean flour, pumice, tripoli, wood flour, walnut shell flour, redwood flour and lignin.

As stated it is frequently desirable to incorporate a surface active agent in the herbicidal compositions of the present invention. Such surface active or wetting agents are advantageously employed in both the solid and liquid compositions. The surface active agent can be anionic, cationic or nonionic in character.

Typical classes of surface active agents include alkyl sulfonate salts, alkylaryl sulfonate salts, alkyl sulfate salts, alkyl-amide sulfonate salts, alkylaryl polyether alcohols, fatty acid esters of polyhydric alcohols and the alkylene oxide addition products of such esters, and addition products of long chain mercaptans and alkylene oxides. Typical examples of such surface active agents include the sodium alkylbenzene sulfonates having 10 to 18 carbon atoms in the alkyl group, alkylphenol ethylene oxide condensation products, e.g., p-isooctylphenol condensed with 10 ethylene oxide units, soaps, e.g., sodium stearate and potassium oleate, sodium salt of propylnaphthalene sulfonic acid (di-Z-ethylhexyl) ester of sodium sulfosuccinic acid, sodium lauryl sulfate, sodium salt of the sulfonated monoglyceride of cocoanut fatty acids, sorbitan sesquioleate, lauryl trimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, polyethylene glycol lauryl ether, polyethylene esters of fatty acids and rosin acids, e.g., Ethofat 7 and 13, sodium N-methyl-N-oleyltaurate, Turkey Red Oil, sodium dibutylnaphthalene sulfonate, sodium lignin sulfonate (Marasperse N), polyethylene glycol stearate, sodium dodecylbenzene sulfonate, tertiary dodecyl polyethylene glycol thioether (Nonionic 218), long chain ethylene oxide-propylene oxide condensation products, e.g.,

O,S-diethyl-a-chloroispropyl-phosphonothioate (Compound No. 3) it will be observed showed selectivity at the lbs./acre rate, affecting oats and leaving wheat relatively unharmed. On the other hand O-phenyl-S-ethyla-chloroisopropyl phosphonothioate showed strong general herbicidal activity at 2 lbs/acre. O-methyl-S-ethyla-chloro-a-butyl propyl-phosphonothioate and O,S-dimethyl-a-chrocyclopentylphosphonothioate both showed general herbicidal activity at 5 lbs./ acre.

I claim:

where R is alkyl of 1 to 8 carbon atoms, R is selected from the group consisting of alkyl of 1 to 8 carbon atoms, phenyl, chlorophenyl and benzyl, R and R taken together are CH (CH ),,CH where n is an integer from 1 to 3 inclusive;

R is selected from the group consisting of alkyl of 1 to 8 carbon atoms and chloroalkyl having 1 to 3 carbon atoms;

R is selected from the group consisting of alkyl of 1 to 8 carbon atoms, alkenyl of 3 to 8 carbon atoms, phenyl, alkylphenyl having 1 to 4 carbon atoms in the alkyl group, chlorophenyl, dichlorophenyl, trichlorophenyl, nitrophenyl and (7113 -o-oHo000,H,,

and X is halogen of atomic weight 35 to 80. 2. O-alkyl-S-alkyl a-chloro a-alkyl alkylphosphonothioate wherein each alkyl group has 1 to 8 carbon atoms.

3. O-alkyl-S-alkyl u-chloro-u-methyl alkylphosphonothioate wherein each alkyl group has 1 to 8 carbon atoms.

4. A compound according to claim 3 wherein each alkyl group has 1 to 4 carbon atoms.

5. O-ethyl S-ethyl 0t-ChiOI'OiSOPI'OPYIPhOSPhOIlOthiO- ate.

6. O-phenyl S-alkyl a-chloro-a-alkyl alkylphosphothioate wherein each alkyl group has 1 to 8 carbon atoms.

7. A compound according to claim 6 wherein each alkyl group has 1 to 4 carbon atoms.

8. O-phenyl-S-ethyl a-chloroisopropylphosphonothioate.

9. O-methyl S-ethyl-a-chloro a-ethyl amylphosphonothioate.

10. O-alkyl-S-alkyl u-chlorocycloalkylphosphonothioate wherein each alkyl group has 1 to -8 carbon atoms and the cycloalkyl group has 5 to 6 carbon atoms.

11. A compound according to claim 10 wherein each alkyl group has 1 to 4 carbon atoms.

12. O,S-dimethyl a-chlorocyclopentylphosphonothioate.

References Cited UNITED STATES PATENTS 2,910,402 10/ 1959 Fairchild 260-961 XR 3,094,405 6/1963 Toy et al. 260-9 (R CHARLES B. PARKER, Primary Examiner ANTON H. SUTTO, Assistant Examiner US. Cl. X.R. 

